What is demand function?

Demand function: Demand function is a function which shows the relationship between demand and other factors like price, income, taste, habits etc.

                          Q_d = f(p,y, H, T, P_s,P_c )

           Where,

                         Q_d = Quantity of good                        T= Tast

                         P= Price                                  P_s= Price of substitute goods.

                        y= income                               P_c= Price of complimentary goods.

                        H= Habit.